Goal: This lesson introduces students to the special properties of trapezoids, especially those of the isosceles
trapezoid.
Real Life Application!Show a photograph of the John Hancock Center, located in Chicago, Illinois. This structure
was the first skyscraper to be built using exterior tube technology, instead of using internal beams as support. Each
face of the John Hancock Center is comprised of six isosceles trapezoids.
Try This! Have each student draw three different isosceles trapezoids. Exchange papers with one student. Ask
students to check one trapezoid to be sure it is isosceles by measuring non-base sides for congruence and equivalent
diagonals. Have correcting students “sign off” on their opinions. Switch papers a second a third time, repeating the
process.
Kites
Pacing:This lesson should take one class period
Goal:The purpose of this lesson is to present special properties of kites.
Visualization!Have students draw two isosceles triangles sharing the same base. By erasing the shared base, they
have just drawn a kite!The shared base represents one diagonal of the kite.
Vocabulary!Using the phrase “ends of the kite” can be misleading for students. The ends do not always mean the
endpoints of the longer diagonal. Be sure students can identify the ends of non-convex kites, and non-traditional
kites (as shown below).
Beat the clock!Have students draw and cut out two copies of a scalene triangle. In one minute, have students form
as many polygons as possible, drawing a sketch of each they form.You can also use tangrams for this activity.
1.6. Quadrilaterals